Reaktion #352186

Reaktionsgleichung

3-fluoro-hydroxy-6-methoxybenzaldehyde

acrylonitrile

→

title compound

Ausbeute 13.6%

3-Cyano-8-fluoro-5-methoxy-2-H-chromen

Ausbeute 13.6%

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeRotary-evaporation of the volatiles
2. 2
   workup.WAITleft a thick, red oil which
3. 3
   Sonstigewas flash-chromatographed on a silica column
4. 4
   Wascheneluted with methylene chloride/n-hexane (4:5)
5. 5
   SonstigeConcentration of relevant fractions gave an impure product (91% GC) which
6. 6
   Sonstigewas crystallized form EtOAc

Vorschrift

Crude 3-fluoro-hydroxy-6-methoxybenzaldehyde (8.0 g) from above, acrylonitrile (13 mL; 193 mmol) and 1,4.diazadicyclo [2,2,2]octane (0.66 g; 5.9 mmol) were refluxed in a three-necked round-bottom flask (50 mL) under nitrogen for 4 h. Rotary-evaporation of the volatiles left a thick, red oil which was flash-chromatographed on a silica column eluted with methylene chloride/n-hexane (4:5). Concentration of relevant fractions gave an impure product (91% GC) which was crystallized form EtOAc to give 1.31 g of the title compound as colourless bars. Mp. 133°-135° C.

Quelle